I’ve run into an issue in BitWarden after importing from LastPass. It seems long numbers get converted into exponent numbers. Not sure if this is just a result of imports, and if it happens to passwords as well.
Did you perhaps open up the export file (I assume its a csv-file) with Excel before importing it into Bitwarden? Don’t. If you want to take a look at its content use Notepad or any other editor or take the look after you imported the file.
Alternatively, it is fine to use a spreadsheet for such tasks as long as you do not allow it to be “helpful”. One of the ways of avoiding “helpful” things like this is to not allow the “don’t worry your pretty little head about this “complicated” stuff” option of letting the spreadsheet “helpfully” decide what the contents of a cell are.
To take a general example, if you tell a spreadsheet not to treat telephone numbers as numbers, but instead treat them as strings, then it will not “helpfully” wreck telephone numbers by doing things like removing leading zeros or converting them into exponential format.